I think you are confused. A "sprint" is not "crunch". Its not a period where we work our asses off, late hours, weekends etc. A sprint is just a period of time.

I think you are confused. A "sprint" is not "crunch". Its not a period where we work our asses off, late hours, weekends etc. A sprint is just a period of time. For us its two, forty hour weeks. Its sustainable and we've been doing it for 16 months. It leads to a very confusing situation, where on the one hand the team is lauded for being the most productive team in the company, and on the other, for not working hard enough. o_0 If you can find anything in any Scrum publication that says otherwise then you can make the No True Scotsman claim, but otherwise you are at best misinformed.